Telephone-transmitter.



No. 722,021. PATENTED MAR. a, 1903 0. HOLMOK. TELEPHONE TRANSMITTER.APPLICATION FILED FEB. 21, 1902.

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INVENTOR.

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WITNESSES.- .nk gd Niinn TATES ATE r rricn.

CHARLES HOLMOK, OF CLEVELAND, OHIO, ASSIGNOR OF ONE-HALF TO WVALTHERKROELLING, OF CLEVELAND, OHIO.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 722,021, dated March 3,1903.

Application filed February 21,1902. Serial No. 95,060. (No model.)

To aZZ whom, it may concern:

Be it known that 1, CHARLES HoLMoK, a citizen of Austria-Hungary,residing at Cleveland, in the county of Ouyahoga and State of Ohio, haveinvented certain new and useful Improvements in Telephone-Transmitters,of which the following is a specification, reference being had thereinto the accompanying drawings.

My invention relates to telephone-transmitters; and its object is toproduce an instrument of this class which shall be extremely sensitiveto sound, while it is at the same time simple and inexpensive.

A further object is to provide means for readily adjusting the parts, sothat the same instrument can be adapted to various conditions and to thedifferent requirements of local and long-distance service.

The invention consists in a certain construction and combination ofparts tobe more fully described hereinafter and definitely set forth inthe claims.

In the drawings, which fully illustrate my invention, Figure l is avertical section through a transmitter embodying my invention, showing astandard in connection with the same, broken away, as indicated. Fig. 2is a rear view of the front plate of the trans- .mitter, showing partsconnected therewith;

and Fig. 3 is a front elevation of the head of the standard.

Referring to the parts by letter, A represents the front case, which isof usual form, provided, as shown, with a forwardly-projecting boss a,having a bore in which is mounted the usual mouthpiece B.

A circular diaphragm O, the margin 0 of which is enveloped between thefolds of a rubber ring D for the purpose of insulating it, ismaintainedin position by a clip E, which is fastened to the inner sideof the case A by means of the small screw a, and a damper F, the tip fof which is covered with the rubber f, is secured to the case A in asimilar manner with the screw a At the center of this diaphragm and onits inner side, as shown,is mounted a button 0, preferably made ofcarbon. This button is connected to the diaphragm C by means of thesmall screw 0',

which passes through the same and also constitutes a terminal for theline-Wire W, which attaches to it, as indicated. This button 0 iscylindrical at its base, and its tip c is preferably hemispherical, asindicated. Proceeding now to a description of the other e1ectrode, itwill appear that within the interior of the front case A a bracket G isfastened by means ofthe screws 9 g, which bracket hasdownwardly-projecting arms 9 near the extremities of which are mountedthe horizontal ad justing-screws 9 These screws are provided withconical tips 9 which are received by the recesses h of the ring H, whichwill be more fully referred to hereinafter. One of these screws isprovided with a milled head g for a purpose that will appear later.

Referring now to the ring H, it is preferably made of brass and ofsubstantially the construction shown. The opening through it is filledby a thick disk It, preferably made of carbon, and this disk h is itselfprovided with an inclined bore 72 Within this bore is carried a ball K,preferably of carbon, which is gently pressed by its own weight againstthe tip 0 of the aforesaid button 0, wherefore an extremely sensitivecontact is made. By adjusting the ring H into inclined positions thecarbon ball K can be made to press with greater or less force, asdesired, against the button a, and the milled head g of the aforesaid.screw g affords means for making such an adjustment with facility. Inthis manner the transmitter may be adjusted to various requirements orpurposes.

The wire W from the line can be secured to the aforesaid bracket G in asuitable manner by means of the binding-nut g joining the wire W in theinsulated cable W, which passes out through an opening 1 in the rearcase L.

The rear caseL is of common construction except that at its rear it isprovided with a plate 1, rigidly secured to it by the small screws Z inwhich plate is fastened a stud Z The outer extremity of this stud isthreaded, as shown at Z where it is mounted in the wall of a cylindricalsleeve R, passing first through a short circumferential slot 3, providedin the head 8 of the standard S. This head .9 is preferably split, as at8 and provided with clamping-screws 8 as indicated. The stud Zsubstantially fills the width of the slot, wherefore the transmitter maybe inclined up or down to adjust the mouthpiece as desired. The cableenters the standard just above the base .9 and passes thence through anopening r into the sleeve R, whence it passes to the transmitter, makingthe connections described.

Behind the ball K a small quantity of raw cotton P or similar materialis inserted in the bore 71. to act as a buffer or backing for the ball.This backing, however, should not exert any material pressure upon theball when in its position of rest and serves simply to guard the ballagainst too violent or too greatadisplacement. In Fig. 2 this backinghas been omitted, as also have some other parts, for the sake ofclearness.

What I claim is- 1. In a transmitter, in combination, a diaphragm, ametallic ring mounted adjacent thereto, a carbon disk carried withinsaid ring and having an inclined bore, a ball carried within saidinclined bore, and resting against said diaphragm, and means foradjusting said ring, substantially as set forth.

for adjusting said ring in different positions, substantially as setforth.

3. In a transmitter, in combination, an insulated diaphragm, a buttoncarried on the inner side thereof and constituting an electrode, acarbon disk, a ring supporting the same, said disk having an inclinedbore, a carbon ball carried within said bore and resting against the tipof said button, screws adapted to support said ring substantially in theplane of said button, said screws affording means for adjusting theinclination of said bore, substantially as set forth.

4. In a telephone-transmitter, in combination, a diaphragm, a buttoncarried on the inner side thereof and constituting an electrode, amember adjacent thereto and having a bore, a carbon ball carried withinsaid bore, a backing of soft material within said bore behind said ball,said member being rotatable about an axis, and means for adjusting saidmember about said axis, substantially as set forth.

5. In a transmitter, in combination, a front case, a diaphragm carriedtherein, a bracket having arms, axially-alining screws mounted in saidarms, a metallic ring supported between the points of said screws, acarbon disk mounted in said ring, and having an inclined bore, and acarbon ball carried within said bore and adapted to rest against saiddiaphragm, substantially as set forth.

In testimony whereof I affix my signature in presence of two Witnesses.

CHARLES HOLMOK.

Witnesses:

F. D. AMMEN, W. KROELLING.

